Ore-boasting furnace



eis-Sheet l A T TORNE Y.

FET AIL.

A. T. LEAVVII ORE ROASTING FURNACE Filed Nov.

A. T. LEAv TT ET AL OBE ROASTING FURNAGE Jan. 15, 1924. Mmm

Filed Nov. 22 1920 5 Sheets-Shea?. 3

' y ATTORNEY.

ORE ROASTING FURNACE Jam.l 15 `1924.

LEAVHTT ET AL 1920 5 Sheets-Sheet 5 Filed Nov'. /22

' r-E lull-illu I WZ la mu@ WI WM @l A TTORN E Y.

Patented Jan. 15, 1924.

FlTATES lAtlZ/t PATENT OFFICE.

AVERY 'Il LEAVITT AND CHARLES H. HUGHES, 0F SYRACUSE, NEW YUlitl/.

ORE-RHAS'IING FUBNACE.

Application filed November 2%, 1920.

.To all fio/tom t muy concern.'

Be it known that we, A vnnY T. LnAvrrT and Crmnnns H. l-luerins,citizens of the United States, residing at Syracuse, in the county ofOnondaga and State of New York, have invented certain new and usefulImprovements in Ore-Roasting Furnaces, of which the following is aspecification.

This invention relates to improvements in ore roasting or sine-ltingfurnaces, and the invention relates particularly to a furnace designedfor the distillation of Zinc.

'lhe object of the invention is to provide ancre roasting furnace of theclass adapted tor continuous operation, which is novel and simple inconstruction, and whereby a greater economy may be effected in itsoperation, and a gif-eater percentage of zinc and byproducts may berecovered, than by any of the older furnaces and methods known mixedwith preheated air, in a series of novel and simple flues which aredisposed in the linings at the opposite sides of the roasting chambers.A further object is to provide novel and simple means for introducingthe unroasted mixture comprising the ore combined with carbon into thetops of the roasting chambers, and also novel means for discharging theresidue or refuse from the bottoms of said chambers, Vthe charging anddischarging of the said chambers being effected by gravity, and beingcontrolled by novel and simple regulating` means, which avoids waste andloss of the products of the reduction. as well as loss and waste of theheat required for the distillation of the zinc. it further object is toprovide means for taking the zinc vapor from each of the roastingchambers independently at different levels or elevations. andcollecting` the liquefied and unliqueiied Zinc in suitable condense=.from which the products of the reduc .on may be readily and convenientlyremoved without interrupting the continuity of the snielting operations.find a further serial No. 425,809.

object is to provide a common chimney which collects the waste heat fromthe roasting ovens and carries it away to be utilized for making steam.

We attain these objects by the means set forth in the detaileddescription which follows, and as illustrated by the accompanyingdrawings, in, which- Figure l is a broken side elevation of the furnacecomprising several independent ore roasting ovens which are combined inone structure. Fig. 2 is a horizontal section and partial top-plan view,the section being taken substantially on line 2-2 of Fig. l', showingcertain of the lining flues in relation to the ore roasting chambers,the connection between the combustion flues and the common chimney, andthe manner of applying the condensers; also showing the d-isposition andarrangement of the tubes employed for discharging the refuse and forprehcating the air before it is mixed with the gas. Fig. 3 is averticalcross-section, taken on line 3 3 of Fig, l. 1l is a similarcross-sectional view, taken on line nel of Fig. 1. Fig. 5 is a similarsectional view, taken on line 5--5 of Fig. l. Fig. 6 is a verticallongitudinal section through the oven linings showing the ovenregulating dampers; also showing one of the recuperating-refuse tubes inrelation to the corresponding refuse hopper.

The foundations upon which the furnace is built are omitted throughoutthe drawings.

ln the drawings, the furnace proper comprises several independent oreroasting units, which are supported by two upright .longitudinal walls22, which may be made of brick or other suitable material. 'lhese wallsare spaced apart to provide a rela tively broad and deep tunnel 8, whichpreferably extends the entire length. of the furnace. The wall 2 isprovided at regular intervals with transverse arched openings 2 foraccess to the tunnel 3 and for facilitating the operation of themechanism which controls the discharge of the refuse. The top of thetunnel 3, except directly beneath the ore roasting chambers l. is closedby an arch formation 3', which partially supports the vertical ovenlinings and division walls, as well as a series of vertically ai'-ranged refuse tube 5, which forni the perforated bottom of the chambers4. The lLubes 5 are disposed in spaced relation in transverse rows incompartments o which loc lll)

are disposed directly beneath the ovens 4, Directly beneath each row oftubes 5 is a' long horizontal rotatable valve 7, the opposite endsofwhich are pivotally supported by the walls 24-2. The valves 7 areprovided with radial wings 7 (see Figs. 3 zand C) and are employed forregulating the discharge of the residue or refuse from the individualroasting chambers 4 which gravitatesthrou'gh the tubes 5'. By this'construction andarrangeinent of the valves 7 substantiallyequa-l'in'easured quantities offv the reduction refuse may be drawn olffrom thjesever'al roasting chambers 4. The valves 7i are provided'withstems 7 n, whichl progect` through the wallQ` and their outer ends arefitted with miteri-gears 7 b, 'which mesh with and are drivenfbylsimilargears 8., the latterbeing lcarried by a common operating shaft 8, which'preferably extends the whole length of the furnace, as shown inlFig. 1. rfhegears S lare preferably shiftable on the shaft S'by meansoflevers 8a vfor regulating the dumpingl of the refuse. The valves 7.y

refractory bricks, as 4, for withstanding the intense heat required forroasting theore and effecting the proper distillation of the zinc. Thetops of the roasting chambers 4 are provided with aplurality of fillingor charging manholes 5, through which the oreand'coalY are admitted bygravity from lorry or charging cars 1'1. Prior to the charging oftheovens 4, the ore and carbon are suitably crushed and mixed in awellknown manner. The cars 11 are operated ontracks 11,`which are laidon top of the furnace. Each manhole 5a is provided with a tight; fittingcover 5", which is held in place by 'suitable fastening means (notshown) for preventing the escape of the he'at'and gases during theroasting'or smelting operations. At the opposite' ends ofthe roastingchambers 4, three or more openings or vents 12 are provided at differentelevan tions for theescape of the zinc vapor, which results from theroasting of the ore, and 'in these openings aredisposed the usualcondensers 13, which receive'the Zinc vapor, and collect the zinc whichliquefies from the proper cooling ofthe vapor. vThe condensers 13decline' at a slight angle, as shown in the drawings for facilitatingthe gravi tation of the' liquidv zinc towards their outer dams arewithdrawn from time to time for the removal of the zinc, and are thenreplaced by new dams. The outer ends of the condensers 13 are fittedwith the" usual prolongs 13, which are usually telescopi cally appliedand readily detachable for removing the blue powder and dust, which isthe residue resulting from the failure of a portion of the zinc vapor tobecome liqueed. Byproviding a number of the condensers 13 and locatingtheml at ditl'erent elevations in the height of the roasting chambers 4,the zinc vapor is more readily and completely carried off, anda greaterpercentage of the zinc is recoverable, than. where fewer condensers areemployed.

The heat for the roasting of the ore is obtained by the burning ofilluminating gas, which may be derived from any suitable gas producer(not shown). The gas is supplied to the furnace by a common main 14,which is disposed along the front side of the furnace and is supportedat intervals by piers 14. The gas is drawn off from the pipe 14 atregular intervals corresponding to the number and location of theroasting ovens 4 by means of regulating valves 15, which are controlledindependently by hand-levers 15. By this arrangement ot the valves 15,the gas for heating any one of the roasting ovens 4 may be turned on orturned olil at will, by the operator simply manipulating the levers 15.After the gas leaves the pi pe 14 it fiows through short horizontal passages 16 into vertical risers 17 disposed centrally in relatively thickdivision walls 18, which are disposed between the adjacent; roastingovens 4. The gas is burned in transverse Hues 19, which are disposed atthe opposite sides of each roasting oven, and are separated from saidovens by the relatively thin refractory linings or walls 4. None of thegas employed for roasting the ore is burned in 4the chambers 4. Theentire roasting of the ore and the distillation of the zinc beingaccomplished by heat which is radiated from the refractory linings 4.After the gas, is ignited, the llames are directed and ytravel back andforth in the fines 19 from thetops to the bottoms of the chambers 4, bymeans of horizontal baille walls 19'; the direction of travel ot' thegas flames being indicated by the arrows in Fi 2l and 4. The gas fromthe risers 17 is admitted to the fines 19 through horizontal passages orports 20 (see Figs. Q, 5 and (i), and the amount of gas flowing to eachset ot' fines 19 is controlled by a pair of refractory dempers or valves'21,' by means of which the operator may regulate the quantity of gas tobe burned, or he may shut olf the supply of gas to one or more of thecombustion flues 19, by closing the correspondlll) uit]

ing dampers 2l. In order to effect the proper combustion of the gas, asWell as to produce the requisite heat for the roasting of the ore, acertain amount of air (oxygen) must be mired with the gas, and in thepresent case the air is preferably admitted to the combustion flues 19and there mixed under suitable regulation. The air for this pur pose ispreferably preheated before it reaches the combustion `tlues 19, andthis preheating is accomplished in a novel and simple n'ianner, asfollows: rlhe supply of fresh air is admitted to the compartments G,`which contain the recuperating tubes 5., through gates Q2, and uponreaching the said compartments the air circulates between and around thesaid tubes, Which are always het, and the temperature of the air israised to a relatively high degree at these ioin's. i rom e ciiliiai'iruii's 'i Y i" l t le th olitiltctthehrt air flows into risersi7, which parallel the gas risers li', and are located near the rearside of the furnace, as shown in Figs. Q and rl`he air passes from therisers lll" through ports into the opposite ends of the flues 19 atdifferent elevations and is there mixed with the burning The volume ofair to be mined. with the is also regulated by similar valves or dampers2l', Which may be moved horizontally for closing the passage 20 leadingto the flues '19. ln order to enable the operator to readily inspect theinterior of the flues i9, which generate the heat for roasting lthe ore,and to ascertain if any regulation is required, We provide a number ofpeep-holes 23 and 23 in the front and rear side VWalls of the furnace,which connect at the differ ent levels with the horizontal or crosspassages 20--20, and which are disposed in line with the severalhorizontal arms of the flues 19. These peep-holes are normally closed byplugs 24. The dempers 2l-2l are operated. by tongs or other suitablemeans (not shown), Wl 'ch may be inserted through the peep-.holes Afterthe gas has burned bach and forth through tbc labyrintl'iiue tlues 19,the Waste products of combustion pass olf rearwardly and downwardlythrough passages into a common. chimney 26, which entends horizontallyparallel to the tunnel 3, and conducts the Waste heat to boilers (notshown) for use in making steam, etc. The Waste heat passages 25 are alsoprovided with peep-holes 27, -which are closed by plugs 27. The chimney26 is formed )y the Wall El and a third `Wall 2l. rlhe tlues 19 of theadjacent roasting chambers el are separated. by the relatively thickdivision walls 18. which serve as reservoirs for retaining the heat ofthe furnace.

rllhe charging' cars lll are preferably arranged ivith a plurality ofdeipiending gated spouts lla, which register with the manholes 5,through which the mixture (ore 'and carbon) gravitate intothe chambersd.

ils the vertical chambers el contain nothing but t ie reduction mixture,which is contimiously being roasted. by the radiated heat from the tluesl), the charging of the chambers naturally occurs more or less regularintervals, and the drawing olf of the refuse and residue through therecuperat ing tlues 5 usually precedes each rccl'iarging operation, soas to provide suitable space at the top of the partially roasted massesfor the reception of the new charges.

ln the present case there are no retorts, such as have been formerlyemployed in many of the furnaces, which in additionfto breakage andbutchering and other troubles have caused considerable loss of eine,through absorption by the retorts and by lil ration through the retorts.rlpplicante utilise the entire space in the roasting chambers -lfor thereduction and distillation of the zinc, andas the vapor comes free fromthe ore, it passes directly into the condensers lll, which areconveniently located at the different elevations, with 'prac tically noloss, as compared with the older furnaces referred to. The feature ofthe non-comnuinication of the couil'iustion tlues 59 with the roastingchambers ll, enables applicants to maintain the heat in the saidchambers-s at substant'ally even temperature continuera y, and the.introduction of the .fresh charges of the mixture at relatively lowtemperature cannot apprcciably reduce the teinpcrature of the. ovens.Vllhe roasting chambers so constructed and arran l. that no cold air isadmitted during` the sinelting operations; the only free vent1 beiiigthe lateral openings l2 which are norin iy closed by the condensers 13.'llhe mixture is confined in the chambers 4l and is roasted and reducedalone by the heat. which is radiated from the refractory walls il. nd asthe agency for the smelting heat onnibustible gas and preheated air,which is cousiu'ncd in the adjacent lines lt) entirely outof the contactwith the mii:- ture, the latter is continuously and effectually roastedfor liberating the zinc vapor, ivhile at the saine time the residuewhich is rich in byproducts-1 suitably reduced with out the usual lossand deterioration such as has been sufered by the various old methi odsof direct tiring, wherein the temperature of the ovens fluctuate Widelydue to the introduction of the cold mixture into the combustionchambers. rtiiiplicantil; are able to so regulate the charging anddischarging of their roasting` chambers that there need be nointerruption of the iistilling Operatioirs While waiting for the normalsmelting temperature to be restored. i

@ur improved ore roasting furnace is er; tremely simple. The provisionof the uptlll Mtl

right roasting chambers 4, which are maintained at a substantially eventemperature by the radiated heat produced by the novel and effectivecombustion flues 19, in which the gas is burned continuously, under thecontrol of novel and adequate regulating means, effects a.- greateconomy in labor, an increases the output of the furnaces withoutincreasing the cost of maintenance and operation, and the furtherprovision of the novel and simple means for discharging and conservingthe refuse and residue, as Well as the preheating of the air enhancesthe value of this invention.

Having thus described our invention, what we claim, is-

1. In a furnace, a casing formed with a plurality of upright roastingchambers, and horizontal flues in which gas is burned for heating saidchambers by means of radiated heat, said flues disposed at the oppositesides of each chamber but not communicating therewith, means for drawingolf the vapor and gases at different elevations in the height of saidchambers, and a plurality of recuperating tubes communicating with thebottom of each chamber for discharging the refuse and for preheating airto be mixed with the gas.

2. A furnace superstructure formed with a plurality of vertical oreroasting ovens having charging manholes in their tops and having ventsfor the escape of vapor and gases arranged at different elevations inthe height of the chambers, the portions of the casing between thechambers provided with combustion flues separated from the chambers byrelatively thin refractory linings which radiate the heat for roastingand smelting the ore disposed in the chambers, a source of fuel gas,means for supplying the gas to said flues, and means for utilizing thehot refuse from the chambers for preheating air to be mixed with the gasin said flues.

3. In a roasting and smelting furnace, a superstructure formed with aplurality of vertical roasting chambers, and combustion lues disposed atthe opposite sides of said chambers adapted to roast the ore in saidchambers by heat radiated from the refractoryv walls which separate theflues from the chambers, the portions of said superstructure disposedbetween the chambers provided With independent gas and air risers whichcommunicatewith said fiues, and the portion of said superstructurebeneath said cha1nbers provided with air-chambers, in which the air tobe mixed with the fuel gas is preheated, and a plurality of recuperatingtubes passing through said air-chambers and coinmunicating with thebottoms of said roasting chambers for discharging the refuse therefrom.

4. In a roasting and smelting furnace, the

combination of a casing formed with a plurality of vertical ore roastingovens, and combustion iues disposed at the opposite sides of said ovens,in which gas mixed with preheated air is burned for heating said ovensby heat which is radiated from the walls which intervene between saidovens and said flues, said casing formed with an air-chamber beneatheach oven, and with a common chimney which draws the waste products ofcombustion downwardly away from said flues, means for preheating the airin said air-chambers, and means for drawing off the vapor product of theroasting and smelting from diiierent elevations in the height of saidovens.

5. In a smelting and roasting furnace, the combination of a casingformed with a plurality of transverse vertical ovens each provided witha plurality of vents for the escape of vapor at differentlevels in theheight of said ovens, the portions of the casing between said ovensformed with serpentine combustion fines which are separated from saidovens by heat-radiating walls, and vertical gas and air passagesdisposed between the adjacent flues, the lower portion of said casingformed with air-chanibers and a common chimney which draws the wasteproducts of combustion from the lowermost portions of said fines, andmeans for preheating the air in said air chambers.

6. In a furnace for roasting and smelting ore, the combination of acasing formed with a plurality of vertical ovens having vents at theiropposite ends for the escape of vapor and gases at different elevationsin the height of said chambers, said casing formed with airchambersdirectly beneath said ovens and with combustion lines which areseparated from said ovens by relatively thin linings, in which gas isburned as it flows back and forth from the tops to the bottoms of saidovens, means for discharging the refuse from the bottoms of said ovens,and means for preheating air to be mixed with the gas in said fiues byradiated heat derived from said refuse. f

7. In a furnace, the combination of a refractory casing formed withvertical ovens, which receive ore by gravity through their tops, andwhich emit the products of distillation at different elevations in theheight of the ovens, and serpentine [lues disposed at the opposite sidesof the ovens, said casing formed with independent risers for carryinggas and air to the lues, tubular refuse exits disposed in the bottoms ofsaid ovens, dampers for regulating the admission. of gas and air to theflues at different levels, valves for effecting the discharge ofmeasured quantities of refuse from the ovens, and means for preheatingthe air by the hot refuse while the latter is passing through saidexits.

8. In a furnace for roasting and distilling zinc ore, the combination ofa casing formed with a plurality of vertical roasting chambers, eachchamber having charging tubes in its top and discharging tubes in itsbottom, the opposite ends of said chambers provided with vents arrangedat dilferent levels for the escape of the products of distillation, saideasing formed with combustion liues disposed close to the opposite sidesof the chambers and with air and gas passages disposed between the fluesof the adjacent chambers and with a common chimney which draws the wasteproducts of combustion away from the lowest level of the flues and saidchambers, said casing between the dues comprising a relatively thiol;wall which serves as a reservoir for retaining the heat of the furnace,and means for increasing, decreasing and preventing the flow of gas andair to each of said iiues.

9. A zinc furnace including a casinp, formed with a plurality ofvertical roasting chambers, and with heating chambers intermediate theroasting chambers, and a recuperator below and communicating with thebottom of each chamber for dischargin?,1 the refuse and for preheatingthe air for the heating chambers.

10. A furnace superstructure formed with a plurality of spaced. verticalroasting chambers arranged to emit the products of distillation atdifferent elevations in the height of said, chambers', the ore in saidchambers being roasted and smelted by heat which is radiated from theopposite side linings thereof, the said heat being produced by similarcombustion flues which are disposed beyond the said linings in which `aswhich mixed with preheated air is burned as it flows back and forth fromthe tops to the bottoms of said chambers, the waste products ofcombustion from said flues being drawn downwardly into a common chimneywhich is formed longitudinally in the base of said superstructure, aplurality of tubes piercing' the bottoms of said chambers for thedischarge of refuse therefrom, the said tubes radiating heat derivedfrom the hot refuse for preheating the air, rotary valves for regulatingand measuring the discharge of the refuse, means for operating saidvalves simultaneously, and means for operating1 said valvesindependently.

11. ln a furnace for roasting and smelting ores, a superstructure formedwith vertical roasting chambers disposed between non-communicatingcombustion flues in which gas is burned for roasting the ore by heatradiated from the linings which separate the chambers from the flues,means for drawingI olf the products of the roast ing from differentlevels in the height of said chambers, means for drawing off measuredquantities of refuse from said chambers without interi-upting` theroasting operations, and means for heating air to be mixe-d with the gasby the het refuse after said refuse leaves said chambers.

12. A zinc furnace including a superstructure formed with a plurality ofvertical roasting chambers and intermediate division walls and twoseparate sets of horizontal heating flues in each division wall, theflues of each set beingr connected in series, and said superstructurebeing formed with vertical air and gas passages in each division wallbetween and communicating; with the flues.

13. In a zinc smelting furnace, the combination of a superstructureformed with an ore roasting oven and with horizontal flues arranged inseries at the opposite sides of the oven, the said oven beingprovidedwith openings for withdrawingl the gaseous products at different levels,and with openings for dischargingrefuse, said superstructure being`formed with separate passages for supplying gas and air to differentparts of each flue, and means for preheating the air before it enterssaid passages by radiated heat derived from the oven refuse.

141-. A zinc furnace superstructure formed with a plurality of verticalroasting; chambers, and with horizontal lieatingfluos in seriesintermediate the roasting chambers, and means for pre-heating thecombustion air by the het refuse.

15. A zinc roasting,` furnace comprising` a number of spaced roastingovens enclosed by a casing, the said casina1 at the opposite sides ofeach oven being formed with a number of connected horizontal`flue-portions, said casing beneath each oven being` formedwith an.air-chamber adapted to supply air to the lines of the correspondingoven, and tubes tapping the bottom of each oven and pass .inethroughsaid airchamber adapted to carry off the oven refuse, and to preheat theair before it enters said flues.

'In testimony whereof we affix our signatures.

lil)

